Abstract
The stress-strain relationship for unsaturated soil is discussed in this paper. Based on the Karube's theory, two types of the suction stress are used, and a new concept on the plastic yield condition and hardening parameter is proposed. The stresses used are called bulk stress pb and meniscus stress pm. Effects of pore water composition for mechanical behavior are presented by using two types of suction stress. As a result, constitutive model is derived by associated flow rule is proposed. Using the derived equations, triaxial compression test and consolidation test with suction change are simulated. The calculation results simulate two types of the test data well.
